Automatic lathe



Feb. 28, A, BECHLER AUTOMATIC LATHE Filed Sept. 20, 1946 INLI Patented Feb. 28, 1950 AUTOMATIC LATHE Andr Bechler, Moutier, Switzerland Application September 20, 1946, Serial No. 698,195 In Switzerland May 3, 1946 1 Claim.

In certain automatic lathes, rocker arms are used to advance and draw the tools working from the sides, the rocking motion of which presents the cutting-tools one after the other to the piece of work. The movements of these parts are also necessary to admit of the tools advancing in their turn to the bar of Work from above.

Up to the present, the rocker in question is without exception pivoted to the support for a work guide used in this type of screw-cutting lathe, the height of which, above the bed supported by the frame, is as small as technically possible. As a result, in this construction the length of the horizontal rocker arm is many times greater than that of the vertical arm, so that if the amplitude of the motion of the latter is to reach a certain limit, the cam lobes on which the follower of the horizontal arm rides have to be made unreasonably big.

The object of the present invention is an automatic lathe in which the aforesaid disadvantage is obviated in pivoting the rocker to the frame of the machine and in guiding it along a slideway of the support for the work guide.

In this way it is possible to reduce the difference of length of the rocker arms considerably and consequently the size of the cam lobes directing them.

The slide-way guiding the rocker will be preferably formed by the vertical face of the support for the work guide, and a plate held at an accurately fixed distance from, and parallel to, the support by means of a bolt with lock-nut.

The drawing shows, by way of example, and in sufficient detail necessary to the understanding of the invention a lathe according to the invention.

Fig. l is an end elevation of the rocker in the lathe, whereas Fig. 2 is a sectional view of the same along the line II--II in Fig. 1.

A support 2 for the work guide 4 with an eyelet 3 is fixed to the frame I. The bar of work is inserted in an opening of the same diameter in the work guide. The chuck is denoted by 6. After correct adjustment, the tools can be tightened in the tool-holders 9, II), which can also be adjusted by means of supporting device on the sides ll of a rocker l2. The axle l3 screwed into the frame I forms the pivot of the rocker. A short box l4 fits very accurately on the axle and the rocker I2 is locked on the latter by means of a clamping-collar l5 and a nut IS. The rocker I2 is provided with a slot I! through which the bolt l8 screwed into the support 2 for the work guide passes, holding the plate I! against the screw 2 head [9 in the position shown by the dotted line in Fi 1.

The horizontal rocker-arm rides through the medium of a follower 2! on the periphery of a cam 22 driven by the cam-shaft 23 of the machine. When this cam turns, its lobes 24, 25, lift the follower 2|, each in its turn, thus making the rocker oscillate about its pivot l3. The distance separating the axis of the pivot and that of the live spindle representing the length of the vertical rocker-arm is but slightly smaller than the distance separating the axle l3 and the point of contact of the follower 2|. In this manner, the required amplitude motions of the rocker can be effected by the use of cam-lobes whose radial dimensions will be of the same order as the said amplitude. This proportion would be quite different, for example, if, as in the case of lathes in general use up to the present day, the rocker were pivoted in a position corresponding to the place where the bolt [8 passes through the support for the work guide.

What I claim is:

In an automatic lathe, a cam comprising lobes, a machine frame, a work guide, a support having a vertical guide-face, mounted on said machine frame and carrying said work guide, a tool-carrying rocker element in engagement with said cam, having a slot and being pivoted to said machine frame at such a distance from said work guide and from the place of engagement of said rocker element with said cam that the amplitude of said rocker element in reach of said work guide is substantially of the same order as the radial dimensions of said lobes, a bolt fixed to said support and traversing said slot substantially in the middle between the pivot point of said rocker element and said work guide, and a plate fixed to said bolt at a distance from said support to guide said rocker element between said plate and said vertical guide face.

ANDRE BE'CHLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,151,379 Flaker Mar. 21, 1939 2,319,963 Wilson May 25, 1943 FOREIGN PATENTS Number Country Date 120,571 Switzerland Sept. 13, 1926 

